<template>
   <div id="app">
      我是vue3
      {{obj}}--{{obj.a}}--{{obj.b}}--{{obj.c}}
      <button @click="addVal">新增</button>
   </div>
</template>
<script setup>
import {reactive} from 'vue'
let obj = reactive({
  a:1,
  b:2
})
const addVal = ()=>{
  obj.c = 3
}
const addVal = ()=>{
  obj.c = 3
}
const addVal = ()=>{
  obj.c = 3
}
</script>
<style>
</style>


 
 
